This invention relates to spectacles or glasses which are provided with no eyewire on rims of lenses of glasses. Such glasses are referred to as xe2x80x9ceyewireless glassesxe2x80x9d hereinafter.
Heretofore, generally, eyewireless glasses as shown in FIG. 6A are known. Eyewireless glasses 100 comprise, as shown in FIG. 6A, a pair of lenses 101, 101, a bridge 102 which is provided to attach the lenses 101, 101, and a pair of temples 103, 103 provided in correspondence to the lens 101, 101. Attachment mechanisms 110 which respectively attach the lens 101 (101) and the bridge 102, and the lens 101 (101) and the temple 103 (103) are provided.
FIG. 6B is an enlarged cross-sectional view taken along the line 6Bxe2x80x946B in FIG. 6A, showing the conventional attachment mechanism 110. As shown in FIG. 6B, the attachment mechanism 110 includes a mount groove 111 formed in a side end portion of the lens 101 which extends in a width direction of the lens 101 (direction perpendicularly intersecting the plane of FIG. 6B), a first through hole 112 formed in a base end of the mount groove 111 (rear direction of the plane in FIG. 6B), an projection 113 formed at a base end of the temple 103, which is engageably fitted in the mount groove 111, a mount element 115 formed with a second through hole 114 in correspondence to the first through hole 112, a fastening screw 116 which is screwed into the first through hole 112 and the second through hole 114 to attach the lens 101 and the temple 103, and a nut 117 which fastens the screw 116.
The mount groove 111 has a rectangular shape in section. The projection 113 has a rectangular shape in section and has such dimensions as to be slidably fitted in the mounting grove 111. With this arrangement, inserting the screw 116 in the second through hole 114 of the mount element 115 and in the first through hole 112 of the lens 101 and fastening with the nut 117 in a state that the projection 113 is engageably fitted in the mount groove 111 enables to directly attach the temple 103 to the lens 101.
It should be appreciated that a description of the attachment mechanism for attaching the bridge 102 and the lens 101 (101) is omitted in this section of prior art since the attachment mechanism for attaching the bridge 102 and the lens 101 (101) is the same as the attachment mechanism for attaching the lens 101 and the temple 103.
In the attachment mechanism 110 having the above construction, the mount groove 111 of the lens 101 is formed by a cutting tool such as a file. Likewise, the projection 113 is formed at the temple 103 by a cutting tool such as a file. Since it is a general matter that a machining precision by such a cutting tool varies from piece to piece, a clearance d is inevitably formed between the projection 113 and a side and/or bottom wall of the mount groove 111 when the projection 113 is fitted in the mount groove 111, as shown in FIG. 6B.
When the clearance d is formed, the bridge 102 and the temple 103 are likely to swing relative to the lens 101 clockwise or counterclockwise about an axis of the fastening screw 116, which may cause undesirable displacement of the bridge 102 and the temple 103 relative to the lens 101.
Further, as shown in FIG. 6B, generally, a right end portion of the projection 113 on the plane of FIG. 6B is not necessarily brought in plane contact with the bottom wall of the mount groove 111 but may be brought in one side contact therewith. When the right end of the projection 113 is rendered in contact with the bottom wall of the mount groove 111, the projection 113 is also allowed to swing about an axis of the contact point, which may cause undesirable displacement of the bridge 102 and the temple 103 relative to the lens 101.
Even if the clearance d between the projection 113 and the bottom wall of the mount groove 111 is as small as, for example, 10 xcexcm, a displacement within such a small clearance causes a large swing of the temple 103 at a distal end thereof since the displacement corresponds to a proportion of the length of the temple 103 against the depth of the mount groove 111 as the displacement is propagated toward the distal end of the temple 103. For example, when the clearance d is 10 xcexcm (0.01 mm), the depth of the mount groove 111 is 1.0 mm, and the length of the temple 103 is 140 mm, the distal end of the temple 103 swings at an amplitude corresponding to 1.4 mm (=0.01 mm (10 xcexcm) xc3x97(140 mm/1.0 mm)). Thus, the distal end of the temple 103 may swing at an amplitude as large the amount corresponding to 2.8 mm.
The swing amount is negligible as far as the glasses 100 are worn. However, when the wearer slightly moves the left and right temples 103 toward and away from each other about an axis of a pivotal point of the corresponding fastening screw 116 when the wearer is about to take off or wear the glasses 100, the temples 103 are likely to be greatly moved toward and away from each other at their distal ends. The glasses having likelihood of causing such an undesired displacement fail to provide high-grade quality, which may lower their commercial value.
The same problem is also involved in a displacement at a connection portion between the lens 101 (101) and the bridge 102.
It is an object of the present invention to provide a eyewireless spectacles or glasses which are free from the problems residing in the prior art.
It is another object of the present invention to provide eyewireless spectacles or glasses which enable to securely attach a frame member to a lens and suppress an undesirable displacement at a connection portion between the frame member and the lens.
According to an aspect of the invention, a pair of glasses is provided with a frame member which support a glass, and an attachment mechanism. The attachment mechanism includes: a mount groove formed in an end portion of the glass, a lower portion of the mount groove being defined by a converging wall; a mount element provided at an end of the frame member; a fastening device which fastens the frame member on the glass by way of the mount element; and a retaining projection formed on the frame member near the mount element. The retaining projection has a leading end which comes into contact with the converging wall of the mount groove at least two or more points when the frame member is fastened on the glass by the fastening device.
These and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description and accompanying drawing.